Results 171 to 180 of about 3,001,234 (205)
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AIR-COUPLED LONG WAVES IN THE OCEAN
Journal of Meteorology, 1960Abstract An IGY tsunami recorder at Texas Tower No. 4 off New York has detected ocean waves of periods from 4 to 10 min which have amplitudes up to 100 times greater than atmospheric pressure oscillations which occurred simultaneously. The latter are shown to be pressure perturbations generated by internal surface waves on a frontal discontinuity aloft.
William L. Donn, William T. McGuinness
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A Study of Air-Coupled Ultrasonic Flowmeter
Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles, 2012A new non-contact flow metering system is developed using air-coupled ultrasonic technique. The principle of the present system is based on the time-of-flight (TOF) ultrasonic flowmeter. The TOF ultrasonic flowmeter has two transducers, a transmitter and a receiver, which are strapped on the outside wall of a pipe.
Keisuke Tsukada +2 more
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Air – coupled ultrasonic transducers with collimators
Ultrasound, 2009Air – coupled planar ultrasonic transducers with collimators can be effectively used for a wide range of distances when air-coupled focussed transducers are being exploited only at the fixed distance. On the other hand use of attached collimators on the planar transducers allows choosing a relatively wide range of spatial resolutions, what is very ...
A. Vladišauskas +2 more
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Air-Coupled Nondestructive Evaluation Dissected
Journal of Nondestructive Evaluation, 2018This work develops a two-dimensional theoretical model to simulate the behavior of a fully non-contact air-coupled nondestructive evaluation system for a thin isotropic plate. The model is divided into transmission, guided wave propagation and reception phase.
Mohammad Said Harb, Fuh-Gwo Yuan
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Characterization of mineral paper by air-coupled ultrasonic spectroscopy
Ultrasonics, 2012A novel technology in the paper industry makes possible to produce paper by using a mineral powder and a polymer instead of cellulose fibers. This new product is called mineral paper, it presents some potential environmental advantages compared with conventional paper, while it exhibit a similar appearance and properties. The purpose of this work is to
T E, Gómez Álvarez-Arenas, D A, Soto
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A comparison of coded waveforms for air-coupled ultrasonic inspection
2013 18th International Conference on Digital Signal Processing (DSP), 2013This paper investigates various types of coded waveforms that could be used for air-coupled ultrasound. These are needed because of the low signal-to-noise ratios that are found in many air-coupled ultrasonic NDT measurements. The various algorithms are described, and their performance in the presence of noise demonstrated.
Marco Ricci 0001 +3 more
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Novel Ultrasonic air Coupled Transducers
1999Airborne ultrasound is currently used for a variety of applications, including distance ranging, level monitoring, broken ply detection and for the limited non-destructive testing of low Z materials (such as green-state ceramics, rubber and carbon fiber composite).
Billson, D. +3 more
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Air-coupled ultrasonic investigation of stacked cylindrical rods
AIP Conference Proceedings, 2012Measurement of the periodicities of diffraction gratings composed of stacked cylindrical rods is explored using an air-coupled ultrasonic technique. Acoustic Bragg scattering from three periodic structures is investigated by means of a polar scan. Consequently, Bragg angles and corresponding frequencies are obtained from angular spectrograms, using two
Jingfei, Liu, Nico F, Declercq
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Wideband air – coupled ultrasonic transducers
Ultrasound, 2004Wideband air – coupled ultrasonic transducers.
R. Kažys +2 more
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A conical air-coupled capacitance transducer for surface imaging
Ultrasonics, 2003This paper describes the construction and operation of an air-coupled capacitance transducer with a conical backplate. This was designed to produce a focal region over an extended distance along the transducer axis. Measurements were performed to examine both the frequency response of the transducer in pulse-echo mode, and the lateral resolution for ...
D A, Hutchins +3 more
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